A man has been found guilty of the manslaughter, but not guilty of the murder, of journalist Phil Cottrell and his teenage co-accused has been acquitted.

Cottrell died from severe head injuries on December 11 last year, the day after he was attacked in Boulcott St, central Wellington, walking home from a night shift at Radio New Zealand.

Nicho Allan Waipuka, 20, had admitted he was guilty of manslaughter for having punched Cottrell, 43, causing him to fall and hit his head on rough concrete. He also took Mr Cottrell’s wallet, which contained $80.

The jury found him not guilty of murder but guilty of manslaughter.

The defence for Manuel Renera Robinson, 18, was that he was on the other side of the road and not involved in the incident. He was acquitted of both murder and manslaughter.

Sue Hollows, Cottrell's sister, said he was taken "in the most tragic of circumstances in an unnecessary and unprovoked attack".

"Nothing would have brought Phillip back however we are extremely disappointed with the outcome.

She thanked police and the Crown for the "incredible job they had done".

Her husband, Heath, said his wife had to endure watching Phillip die a slow death.

"In the hospital for 17 hours, I watched my wife hold Phillip's hand and the next day he died," he said.

"It took him over an hour and a half - it's just so traumatic.

"We don't hold it against the jury - it's just the system and we are just a little disappointed the streets aren’t any safer than they were a year ago."

Lawyers for the accused made no comment, as did family of the accused.

Robinson left court from a side entrance wearing a baseball cap and got into a parked car without making any comment.

The officer in charge of the case, Detective Senior Sergeant Scott Millar, said he was disappointed with the result and it had been a difficult trial.

It was too early to say if police would appeal, he said.

But the Crown said both men had told friends that they had kicked Cottrell and both should be found guilty of murder, if the jury accepted that evidence.

During the trial some witnesses withdrew damaging statements they had earlier made to police. Some said they could not recall making the statements, that they contained lies, or that they felt police forced them to give the statements.

The Crown did not allege that either Waipuka or Robinson had meant to kill Cottrell, but that they meant to cause bodily injury knowing it was likely to lead to death, and that they consciously took the risk of causing death.

Either would be guilty as a party to murder if they did or said something intended to assist or encourage the other knowing what was intended. Mere presence, or not taking steps to prevent an attack, was not enough to be a party to the crime.

Each man tried to shift the blame to the other.

- © Fairfax NZ News